Pfizer said Monday that an early peek at the data on its coronavirus vaccine suggests the shots may be a surprisingly robust 90% effective at preventing COVID-19, putting the company on track to apply later this month for emergency-use approval from the Food and Drug Administration.

Coronavirus transmission from minks to humans does not necessarily mean the disease will become more dangerous, but scientists are on their guard in the wake of an astounding announcement from Denmark.

The majority of people infected with SARS-CoV-2 appear to actively shed infectious virus for about 8 days, but there is a wide range of variability from person to person. Understanding how long people can remain actively infected is important, because it provides new details about a disease and a virus that are still not well understood and informs public health decisions.